The man who advised the Cronulla board to sack four staff members and stand down coach Shane Flanagan claims the Sharks players under suspicion of taking banned substances may have an "arguable defence" in attempting to avoid an ASADA ban.

Hired by Cronulla in the wake of ASADA's investigations into practices at the club in 2011, Alan Sullivan QC's role was primarily seen as one to help the NRL club avoid litigation from the players.

The threat of legal action followed revelations ASADA had 14 Sharks players in their sights, with the continual rhetoric coming from the playing group being that they never knowingly took any banned drugs.

While reticent to provide too much detail as to a possible defence, Sullivan, speaking Tuesday on Sydney radio station 2GB, revealed he had advised the players' legal representatives as to how their clients could possibly avoid drug bans.

"I think the players may have an arguable defence," Sullivan said.

"We don't know everything ASADA has got, but it's critical to the ASADA case that they prove that the substances were prohibited.

"Just because the players are told they're taking an Aspro doesn't mean in fact they took an Aspro."

Sullivan said it was up to the players to show "utmost caution" in relation to any substance which entered their body. But if that caution has been shown, the onus then falls to those in control of the substances being administered.

"The club may well have thought that the utmost caution may have failed to have occurred on this occasion," Sullivan said in reference to the removal of football staff members.

He said while the decision to stand down Flanagan and sack four football staff members may not have been popular with players or fans, he described the call as "brave and responsible".

South Sydney fullback Greg Inglis - whose side takes on the Sharks at ANZ Stadium on Monday night - sympathised with Cronulla's plight, but warned players had to take accountability for substances taken.